Aside from the local cryotherapy carried out since a few years ago with a cold treatment gas, e.g. for treatment of rheumatic diseases, a cryotherapy on the entire body is also carried out with some forms of illnesses. Air is hereby cooled in heat exchangers, with the aid of liquid nitrogen, and injected into closed treatment space. This treatment space which is designed as a chamber or cabin has walls of insulating material and connections for the supply and removal of the treatment gas. Such a chamber is, for example, disclosed in the Japanese utility patent No. 168 125/81. This concept finds little approval, however, from doctors as well as from patients. The reasons for this are manyfold. The patients object to the lack of direct contact with the doctor since during, treatment, only an indirect contact thru speaker arrangements is possible. The strong buildup of fog in the chamber further intensifies this impression of lack of direct contact. Another disadvantage is the cooling in the area of the patients head. Aside from this one must, by special means, avoid the inhalation of cold air. Such chambers require a high investment cost. Because of the long buildup time, there is a need for continuous operation, as a result of which relatively high operation costs result. The supervision of the patient during treatment is expensive.